MARK COLVIN: What a difference a day makes. After thanking Pakistan for its cooperation on the raid, the Obama administration is now demanding an explanation from the Pakistani government on how Osama bin Laden was able to hide in the country for so long.

During a briefing at the White House, president Obama's counter-terrorism adviser John Brennan said that it was inconceivable that bin Laden did not enjoy a support system in Pakistan.

And here, the former Australian defence minister Joel Fitzgibbon says the Federal Government must find out whether Pakistan was complicit in harbouring Osama bin Laden. He says it's imperative if we're to understand the prospects of success for Coalition forces in Afghanistan and the risk to Australian troops. Mr Fitzgibbon says it's hard to make that assessment if a big piece of the jigsaw is missing.

The Labor MP spoke to Alexandra Kirk in Canberra.

JoeL FITZGIBBON: Well of course I make no judgement. I'm in no position to know what the Pakistanis knew or didn't know. I suspect very strongly that the administration does know but if one were to come to the conclusion that the Pakistan government was complicit in some way or were harbouring bin Laden then it would be hard not to be more pessimistic about their willingness or determination to rein in the Afghan Taliban in their own border regions.

And of course if that's not done, it would be hard to be optimistic because success in reining in the Afghan Taliban in the North-West Frontier Province is absolutely critical to future success in Afghanistan.

ALEXANDRA KIRK: The Prime Minister has cited president Obama's words yesterday that he thanked Pakistan for the assistance that helped lead the Americans to where Osama bin Laden was. That doesn't give you any heart?

JoeL FITZGIBBON: Well it's encouraging and it's worth remembering that no nation has lost more of its people, civilians, to jihad at the hands of the extremists than has Pakistan, mainly at the hands of the Pakistan Taliban. So that does give one encouragement. I just simply make the point again that we need to be reassured, if our troops are going to continue to put their lives on the line in Afghanistan, that one of our key partners, Pakistan, is absolutely committed to the project.

ALEXANDRA KIRK: Do you believe that it's incumbent on the Government, the Australian Government, to find out who knew Osama bin Laden was in Pakistan?

JoeL FITZGIBBON: Well it would be incumbent upon the Government to make its views known strongly to the US administration and our other allies, partners and friends. I'm fortunate to be able to speak a little bit more freely on these issues. I see this through the prism of our involvement in Afghanistan. I always want to make sure that if we're going to have people there on the ground, putting their lives at risk on a daily basis, that we fully understand the prospects of our success.

ALEXANDRA KIRK: Do you think the Government's going to have to wait until the Americans tell the Government what actually went on?

JoeL FITZGIBBON: I believe the administration probably knows now how long bin Laden had been there and what the Pakistanis knew about it.

ALEXANDRA KIRK: But do you think the Federal Government, the Australian Government knows?

JoeL FITZGIBBON: Oh I suspect not. I suspect the administration is playing this one very, very close, understandably so. And of course it's understandable that they kept the deployment very, very close.

ALEXANDRA KIRK: Do you think it is time that the US government told the Australian Government what went on?

JoeL FITZGIBBON: Well I'm not sure there's any urgency about it. But for us to be eyes wide open on our future involvement in Afghanistan we need to know what the prospects of success are, we need to know what the risks are and the extent to which Pakistan is committed to the project is obviously critical to understanding those things.

ALEXANDRA KIRK: If it turns out that the Pakistan government knew where Osama bin Laden was and turned a blind eye, what then?

JoeL FITZGIBBON: Well nice try, Alex. Not for me to say. Suffice to say that the administration in the US would face some very, very tough decisions. I mean it's just so important to international security, our own security here in Australia that we have a democratic and stable Pakistan.

So, you know, an idea of punishing Pakistan in some way, for example withdrawing aid, might not necessarily be a good outcome for the immediate region and indeed the safety and security of Australians and westerners everywhere. So no easy answers there for the US but at this point in time of course it's quite a hypothetical question.